The present invention relates to a package labeling system and, more particularly, to a device for receiving an adhesively backed label from a label transport with the adhesive side of the label facing upward and, thereafter, applying the label to the bottom of a package through a label application opening in a package support.
The present invention is particularly useful in applying adhesively coated labels to the bottom of a package. The Universal Product Code (UPC), now in general use in the retail food industry, facilitates automated checkout in grocery stores and supermarkets. The code is a bar code pattern which, for prepackaged goods, specifies in machine readable notation the manufacturer and the item. With prepackaged products, this code is typically printed on a side of the product package. At the checkout stand, the checker passes the bar code symbols over a scanning arrangement, of a type known in the art. The scanning arrangement reads the coded information and transmits it to a computer which determines the cost of the item being sold and supplies this information to a checkout register for totalization. Additionally, the computer may keep track of the items sold for inventory purposes.
Since, however, between ten and thirty percent of the items sold in grocery stores are random weight items (e.g., meat, produce, cheese, etc.), UPC labels must also be printed and applied to such items in order for an automated checkout system to be employed effectively. In prior art weighing and labeling systems, a Universal Product Code printer has been connected to the scale system upon which goods are weighed after being packaged in the meat and produce department of the grocery store. The label printed by the UPC printer is received from the printer by a label transport, such as shown in U.S. Pat. No. 3,985,603, issued Oct. 12, 1976, to Berner, assigned to the assignee of the present invention. In the device disclosed in the Berner patent, the label is ejected from the label transport into a catching device and a label applicator nozzle, having a suction opening therein, lifts the label from the catching device and applies it to the bottom of a package through a label application opening in a package support.
U.S. Pat. No. 3,985,605, issued Oct. 12, 1976, to Treiber et al, discloses such a label applicator and catcher device, as well as an associated package transport system which conveys a package into proper location for application of the Universal Product Code label to the bottom thereof. The label application apparatus of the present invention is designed to be used in the system of Treiber et al and provides improved label application.
In the Treiber et al system, a label applicator nozzle defines a suction opening which is connected to a source of partial vacuum. Air flows into the suction opening at a relatively low flow rate. Since the label ejected from the label transport is caught by a catcher device, however, the partial vacuum required for the Treiber et al applicator need not be sufficient to catch the label in flight during ejection from the transport, but only sufficient to hold it on the applicator nozzle during the upward movement of the applicator. As the applicator nozzle reaches the upper limit of its travel and the label is pressed against the bottom of the package, the partial vacuum is momentarily reversed to assist in removing the label from the applicator nozzle.
The label applicator arrangement of Treiber et al, however, has several drawbacks. Although the catcher device is designed to contact a label only at non-adhesive bearing points, invariably some of the adhesive material from the back of the label is present along the label edges. Since these edges may come into contact with portions of the catcher device as a label is caught, build up of the adhesive on the catcher device will result over a period of time. After sufficient adhesive build up, labels will tend to stick to the catcher device and operation of the label applicator system may become unreliable.
Additionally, in a label applicator system, such as shown in Treiber et al, in which an adhesively backed label is held on a flat surface as the label is appled to the bottom of a package, the label may not be firmly pressed against the bottom surface of a package where this surface is curved. The bottom surface of a package may typically be curved or bowed where meats or produce are placed in a paper tray, termed a "boat," and a sheet of transparent wrapping material wrapped tightly therearound. If the wrapping material is wrapped too tightly around the package, the bottom of the package will tend to bow upward at its periphery as a result of the tension in the wrapping material. As the applicator nozzle moves upward into contact with the bottom of such a package, it is apparent that only a portion of the label may actually be pressed against the bottom of the package, since the top of the applicator nozzle will remain horizontal. Adequate pressure for adherence of the label to he package bottom may, therefore not occur.
Accordingly, it is seen that there is a need for apparatus for receiving an adhesively backed label from a label transport and applying the label to the bottom of a package, without intermediate label catching structure on which adhesive may accumulate. Further, there is a need for a reliable label applicator for applying a label to the bottom of a package, regardless of whether the bottom of the package is flat or bowed.